1. Field of the Invention
The present invention relates to tufting of rugs, carpets and the like and utilizes a pneumatic system which may be used in various types of tufting systems, however, it has particular utility in the Spanel et al multi-color selection system described below.
2. Prior Art
The present invention offers modifications to some embodiments disclosed in U.S. Pat. No. 3,554,147 which issued to Abram N. Spanel and George J. Brennan on Jan. 12, 1971 and U.S. Pat. No. Re 27,165 which issued Aug. 10, 1971 to Abram N. Spanel and Loy E. Barton, Abram N. Spanel being the inventor of the subject matter of the present application.
U.S. Pat. No. Re 27,165 discloses a pneumatic system in which yarn strands and/or discrete bits of yarn are transported pneumatically to a loading station where they are applied by a bit-applying element to the backing layer. Here, multi-color selection of yarn bits is enabled by a magazine thus offering a varied color selection to each of the guide tubes through which yarn is transported to the bit-applying elements in their loading position.
The aforementioned U.S. Pat. No. 3,554,147 shows an alternative system to U.S. Pat. No. Re 27,165 which provides for the simultaneous selection of bit-lengths of yarn of different colors for each tufting cycle at each individual needle station. This is accomplished by having yarn from as many sources of color as desired fed through channels which lead into a common channel adjacent the loading station. The capability of cutting a bit-length of yarn before, during or after threading of the bit-applying means and before or during tufting is disclosed. Since the cutting function may take place in close proximity to the loading station and after a particular yarn strand has been fed into the common channel, U.S. Pat. No. 3,554,147 discloses a pull-back system to remove at will, the strand of yarn from the common channel leading to the loading station when a color change is desired.
The system disclosed in some embodiments of aforementioned U.S. Pat. No. 3,554,147, wherein yarn was severed into yarn bits while in tubes or channels when under the influence of pneumatic pressure, was found lacking in some aspects when employed with multi-color selection systems. Accordingly, it is one of the objectives of this invention to provide for increased utility when so employed, as will be clear from the following. To admit a cutting element into pneumatic passageway, it is necessary to have an opening through which the cutting element may operate. This very opening will diminish the efficiency of the pneumatic system, if allowed to remain open during the transport of the yarn. Further, in the Spanel et al multi-color, cut-pile systems, it is desirable to have cutting means adjustable to produce variable pile heights in the manufactured rugs, such adjustment tending to also diminish pneumatic efficiency.
Pneumatic tufting systems such as contained in U.S. Pat. No. 3,216,387 issued Nov. 9, 1965, U.S. Pat. No. 3,217,675 issued Nov. 16, 1965 and U.S. Pat. No. 3,386,403 issued June 4, 1968, all to Joe T. Short, are directed to continuous tufting methods without the multi-color capability of changing yarns prior to each tufting cycle. Such system do not provide a cutting-before-tufting operation comparable to that disclosed in the Spanel et al systems.
U.S. Pat. No. 3,389,667 which issued June 25, 1968 to Helmet C. Mueller discloses the transportation of yarn by positive pressure through hollow needles which are similar to those used in the Short patents and are to be distinguished from the Spanel et al needles which are not hollow and are transversely threaded through needle eyes. Mueller cuts the yarn while it is still in the hollow tube-like needle, and further he neither shows nor teaches a means to prevent pneumatic pressure loss at the cutting station.
The Stanley Shorrock U.S. Pat. No. 3,595,186 issued July 27, 1971 also discloses the use of hollow needles as do the aforementioned Short and Mueller patents whereas the Spanel tufting systems use needles that clearly are not hollow, and moreover are transversely threaded through needle eyes.
Furthermore, Shorrock's arrangement is dependent upon a combination of mechanical and pneumatic feeding means whereas the Spanel et al system utilizes solely pneumatic feeding means.
Also, Shorrock provides yarn bits of uniform length and does not show nor teach the capability to provide variable lengths of yarn bits as is clearly and fully disclosed in the teachings of Spanel in the present application.
A need is thus present for an integrated, highly efficient system for placing a discrete bit in a loading position relative to a tufting member which includes: cutting the yarn into a yarn bit with a cutting means and preserving the efficiency of the pneumatic system while performing such a cutting function, such means being additionally adjustable to provide yarn bits of varying lengths; improving the efficiency of the pneumatic system at the needle station and at the same time providing means to positively control the yarn before and after tufting.